The as-yet unnamed concept is widely tipped to preview the design of the brand’s Z4 successor.

As is so often the case with teaser sketches BMW has been careful to reveal little about the concept’s final form, though the moody silhouette displays classic roadster proportion with a low bonnet, long dash-to-axle ratio (the space between the front wheel and the front door), and a short rear deck.

The roadster also appears to show a svelte low windscreen and integrated rear roll hoop structure, with a hint of low ‘shark nose’ front end that imitates the style of the larger 8 Series that BMW unveiled earlier this year at Italy’s Concorso d’Eleganza Villa d’Este.

The previous BMW Z4

If the Pebble Beach concept is a Z4 replacement it will be the first public display of BMW’s collaboration with Toyota, which will lead to a new-generation Supra for the Japanese brand, while BMW will is expected to stick with the Z4 badge for its convertible.

Although still to be confirmed, the new BMW is tipped to return to a soft-top, ditching the previous car’s folding hard top, powered by a range of turbocharged four and six-cylinder engines with rear wheel drive and the possibility of hybrid assistance.

While the Pebble Beach Concours d’Elegance is famous for its rare and exclusive vintage vehicles, BMW has a history at the event, displaying a race-liveried version of its 2002 Hommage at last year’s event, and a Zagato-designed interpretation of the previous Z4 as part of the 2012 concours along with other concepts and production previews over the years.

Further details of the Pebble Beach roadster will be revealed at the Californian concours on August 17 where we’ll find out just how close to a production reality this latest concept really is.